WHO stresses prevention over remediation for drinking-water safety

Sep 23, 2004 (CIDRAP News) – Calling for better prevention from catchment to consumer, the World Health Organization (WHO) on Sep 21 issued new guidelines to ensure drinking-water safety worldwide.

The third edition of the Guidelines for Drinking-water Quality (GDWQ) emphasizes prevention, a philosophical shift from the remedial approach embodied by testing water samples for chemical and biological contaminants. Contaminated water is too often found only after people get sick or die, according to a press release announcing the guidelines.

The challenges of providing safe drinking water worldwide are growing, the press release said. The guidelines are intended to help regulators and water service providers maintain and improve drinking-water quality.

The new guidelines recommend a holistic approach, saying it "increases confidence in the safety of drinking water. This approach entails systematic assessment of risks throughout a drinking-water supply—from the catchment and its source water through to the consumer—and identification of the ways in which these risks can be managed, including methods to ensure that control measures are working effectively."

Efforts will include protecting local wells or water reservoirs from human or animal waste and checking basics such as changing water filters. The guidelines also include reviewed and updated recommended values for chemical limits in drinking water for more than 100 chemicals. It also sets out feasible approaches to "rule out" some chemicals and prioritize others using readily available information, the press release said.

"This . . . is the most significant water-related public health development since the introduction of chlorine," said Dr. Michael Rouse, International Water Association (IWA) president, in the WHO press release.

WHO offered regional examples of prevention successes and outbreaks, including:

  • A recent study of 400 households in a Malawian refugee camp indicated that using a water container with a cover and a spout decreased contamination, resulting in 31% fewer cases of diarrheal disease in children younger than 5.
  • The United States and Canada have seen several Escherichia coli O157 outbreaks as well as incidents involving Campylobacter and Cryptosporidium in recent years.
  • In Asia, arsenic and/or excess fluoride in water affects more than 120 million people.
  • Water-linked disease outbreaks occur even in highly developed nations, including Norway (72 outbreaks from 1988 through 2002) and the United Kingdom (26 outbreaks from 1992 through 1995).
  • The United States and Canada have seen several E coli O157 outbreaks as well as incidents involving the spread of Campylobacter and Cryptosporidium in recent years.
  • Only 24% of the urban population of Latin America and the Caribbean have some water quality control surveillance system.

Edward Ohanian, PhD, Director of the Health and Ecological Criteria Division of the Office of Science and Technology/Office of Water for the US Environmental Protection Agency, helped WHO determine if guidelines needed to be changed for specific contaminants.

While the United States generally has preventive procedures in place, new details about some contaminants may prompt changes, Ohanian told CIDRAP News.

Developing countries are increasingly striving to come into line with WHO guidelines, he added. Countries that lack expertise and/or resources, however, continue to face hurdles in complying with the recommendations.

See also:

WHO news release
http://www.who.int/mediacentre/news/releases/2004/pr67/en/

Full text of guidelines
http://www.who.int/water_sanitation_health/dwq/gdwq3/en/

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